The couple that crumbled in the wake of Stewart's transgressions with her "Snow White and the Huntsman" director have reportedly rekindled their relationship, just in time to hit red carpets around the world to promote the final installment in the "Twilight" saga, "Breaking Dawn -- Part 2," out next month. Last week, Stephen Colberttweeted his analysis of the news: "Robert Pattinson and Kristen Stewart are back together! Wow, and so close to the release date of their new movie. That's lucky!"

Indeed. The history of Hollywood hookups is rife with examples of people who came together -- or at least let relationship rumors linger -- at convenient times in their careers:

Taylor Swift and Jake Gyllenhaal

'Twas a love story that was, perhaps, pure fiction. Swiftenhaal came to be when she had an album to hawk ("Speak Now") and he had a movie to promote ("Love and Other Drugs"). But in January 2011, the two ended their weeks-long "relationship" -- in quotes because their romance appeared to consist of little more than meet-ups over coffee, and neither of their reps ever confirmed the two were actually dating.

Jessica Simpson and Billy Corgan

In December 2009, just before she and her father began a press push for her VH1 series, "The Price of Beauty," Jessica Simpson was linked to an unlikely paramour -- Smashing Pumpkins frontman Billy Corgan. She's blond, he's bald. She's country poppy, he's dark alt-rock.

Over the course of a month, Simpson tweeted about a potential collaboration with Corgan and gushed about how she admired his "enlightening outlook on faith." They were photographed together, and sources spoke anonymously about them "getting to know each other." Then, as fast as Simporgan swept into the public conciousness, the "couple" fizzled.

Heidi Montag and Spencer Pratt

It's not unreasonable to think that Heidi Montag and Spencer Pratt (of MTV's "The Hills") signed a pact in 2006 to embark on a relationship for the sole purpose of seeing how long the media would watch them. Through their wedding, her plastic surgery, their separation and their reconciliation, we did. And look how far it's gotten them: Montag's hosting the third anniversary party of a Las Vegas strip club later this month.